The present invention relates generally to machines and other apparatus and to processes used to clean dirty product of fines and other undesirable particulate matter and specifically to machines and processes incorporating a vertical drop through an upward air flow therethrough and through a plurality of transverse air flows therethrough that remove the fines and/or foreign matter present in the product therefrom.
Product cleaning to remove fines and other undesirable materials is a well known and long used process. A variety of machines are used for this purpose. One type involves the use of rotating screens to sort or filter the desirable from the undesirable product. Another type involves the use of an air flow through the falling product to blow away light weight fines and other undesirable materials.
An example of the latter type of product cleaner, also called an aspirator, is shown in U.S. Pat. No. 5,685,434 to Ackerman, which is assigned to the same assignee as the present invention, and which is commonly referred to as a vertical drop, multi-pass cleaner. As shown in that patent, a product stream including fines and other undesirable material is introduced into the product cleaner. The product stream flows downward under the influence of gravity and an upward and transverse moving air flow blows the lighter fines and undesirable particulate matter out of the product stream. One of the features disclosed in the Ackerman ""434 patent is the use of flow control dampers on the inlet side of the air flow path in an attempt to regulate the air flow entering the product cleaner at various points along the path of the downwardly falling product stream. The goal in doing so is to control the air flow substantially equally through out the downward falling path of the product to be cleaned.
It has been found that providing a means for controlling the air flow entering the cleaner does not, in fact, afford the desired ability to control the airflow.
It would be desirable to have a product cleaner that enabled the operator to precisely control the transverse airflows.
It is an object of the present invention to provide new and improved apparatus that is not subject to the foregoing disadvantages.
It is yet another object of the present invention to provide a vertical drop cleaner that enables the operator to control the air flow, particularly the substantially transverse air flows, through the free flowing product.
The foregoing objects of the present invention are provided by an improved product cleaner including a vertical upward and transverse airflows to remove fines and other undesirable particulates from the product. An apparatus in accord with the present invention includes a product inlet and a product outlet disposed substantially therebelow. The apparatus further includes a plurality of transverse airflow inlets and a plurality of transverse airflow outlets with the outlets including a plurality of individually movable dampers that open and close the outlets for the individual control of the airflow through each outlet.
The foregoing objects of the invention will become apparent to those skilled in the art when the following detailed description of the invention is read in conjunction with the accompanying drawings and claims. Throughout the drawings, like numerals refer to similar or identical parts.